1. Field of the Invention
The present invention relates to an image processing and display method, and more particularly, to a method utilizing Brightness Preserving Bi-Histogram Equalization (BBHE) to process images for improvement of image quality under various conditions of the ambient light.
2. Description of the Prior Art
Flat panel display devices have recently increased in popularity, among which include plasma display panel (PDP) devices and liquid crystal displays (LCD). For portable devices, a small-scale or middle-scale flat display device is usually applied. The display device must be able to adjust the brightness of the backlight in order to display a discernable image under various conditions of the ambient light in the environment. This is because a portable device will encounter various ambient light conditions depending on the current operating environment. However, the adjustment of brightness for the backlight may result in a decreased overall image quality for the display device. The related prior art provides a method for improving poor image quality by displaying more bits in the display device while decreasing the brightness of the backlight. For example, the number of bits is increased from eight bits to ten bits to compensate for problems caused by dimness of the backlight, such as a low contrast, low chromatism, or low saturation etc., to improve the image quality and resolution. However, displaying an image with increased bits also increases cost.
Additionally, in U.S. Pat. No. 6,762,567, a driving device for a plasma display panel is disclosed. When the average brightness of the image is decreased by adjusting the backlight, the driving device changes the voltage level, width, and frequency of the voltage driving pulse signal to improve the degraded image quality caused by the adjustment to the average brightness. However, increasing the width and frequency of the pulse not only results in more power consumption, but also degrades overall uniformity of the panel.